This invention relates to a vehicle seat assembly and in particular to a seat assembly with an armrest attitude adjustment mechanism to enable the armrest to be maintained in a normal, generally horizontal, position when the seat back is reclined within a given range of reclined positions.
It is not uncommon for vehicle seats, in particular bucket seats, to include a reclining feature to enable the angle of the seat back to be varied from a generally upright position to a reclined position within a given range. This enables the seat back to be adjusted, as desired, to accommodate various size occupants.
It is also not uncommon for bucket seats, particularly in vans, pick-up trucks and other multi-purpose passenger vehicles, to be equipped with armrests which extend forward from the seat back on one or both sides of the seat back. Typically, the armrest is positioned in an operative position relative to the seat back such that the armrest extends horizontally from the seat back when the seat back is in its upright position. When the seat back is reclined however, if the armrest is not adjustable, it will no longer be horizontal but will be upwardly inclined from the seat back.
Accordingly, it is an object of the present invention to provide an attitude adjustment mechanism to enable the armrest to be adjusted downwardly to a horizontal position when the seat back is reclined.
The present invention accomplishes this objective by utilizing a cam lock mechanism which enables the armrest to be positioned anywhere within a range of operative positions to accommodate a range of reclined seat back positions. The cam lock mechanism includes a cam plate fixed to the seat back and a pawl plate rotatably mounted to the armrest. The pawl plate is biased into engagement with the cam plate such that an edge surface of the pawl plate is in engagement with a edge surface of the cam plate to create an interference relationship between the cam plate and the pawl plate. The cam lock mechanism is a one-way acting lock which prevents downward rotation of the armrest but does not restrict upward rotation of the armrest.
A release mechanism is provided to move the pawl plate out of engagement with the cam plate to enable the armrest to be adjusted downwardly. The armrest can also be raised to a position parallel to the seat back in which the pawl plate edge surface no longer engages the cam plate edge surface. This enables the armrest to be lowered from the raised position without first actuating the release mechanism. When the armrest is lowered to the range of armrest operative positions, the pawl plate will engage the cam plate to lock the armrest in place. Further downward adjustment of the armrest requires actuation of the cam lock release mechanism.
Further objects, features and advantages of the invention will become apparent from a consideration of the following description and the appended claims when taken in connection with the accompanying drawings.